1. Field of the Invention
The present invention relates to a semiconductor device with field-effect transistors.
2. Description of the Background Art
Conventionally, semiconductor devices using field-effect transistors have been manufactured. One field-effect transistor is provided in an element formation region surrounded by an element isolation part when viewed in the direction perpendicular to the main surface of a semiconductor substrate in such semiconductor devices. A single P-channel type transistor, for example, is provided in the element formation region and no other elements are provided in this structure.
It is necessary to individually separate transistors by means of an element isolation part in a semiconductor device having a structure that only a single field-effect transistor is formed in an element formation region as described above. Therefore, the area of the semiconductor device cannot be reduced in the direction parallel to the main surface of the semiconductor substrate.